This invention relates to a process for separating chlorine gas from a mixture of gases. In particular, it relates to a process in which a mixture of gases containing chlorine is cooled to less than 0.degree. C. and is contacted with ice, which results in the formation of chlorine hydrate on the ice. To release the chlorine gas from the chlorine hydrate, the ice is separated from the mixture of gases and is heated and/or the operating pressure on the ice is reduced.
In manufacturing chlorine, mixtures of gases that contain chlorine are inevitably produced. While the other gases in the mixture may be harmless, chlorine is toxic and must be removed from the mixture before the mixture can be released to the atmosphere. Many techniques have been used to separate chlorine from mixtures of gases, the particular technique chosen depending upon the concentration of chlorine in the mixture and the other gases that are present.
One technique is to pressurize the gas mixture while adding cold water to form solid chlorine hydrate crystals. The solid chlorine hydrate is separated from the remaining gases and the pressure on it is relieved and/or it is heated, which releases the chlorine. Liquid water is used in this process because it is believed that chlorine gas is insoluble in ice.